Mizuno Women's Breath Thermo Bio Leg Running Tight 92% Polyester/8% Spandex, 230 gm, 7% Polyacrylate Fill Breath Thermo - This is a unique type of insulation fabric which generates heat from the absorption of moisture DFcut - Dynamic Function Cut - Mizuno's design technology that coordinates fabric characteristics with specific sport patterns, eliminating stress and allowing unrestricted potion for better performance Wash separately, hang dry when wet, don't tumble dry, wash inside out, do not use softeners, do not bleach. Made in Indonesia.. Heat is generated via a chemical exchange between perspiration and the properties of the Breath Thermo Fabric. This is especially useful for protecting the human body from cold temperatures.